对抗红外热成像反舰导弹的方法探讨

本文从红外热成像反舰导弹对舰船威胁的实际情况出发，详尽分析了红外热成像反舰导弹成像系统的工作原理、导引头的制导机理、目标识别方法及工作特点，并在此基础上提出了相应的对抗思路及实施方法。     

新型滚刀的研制

针对东风4机车上的从动齿轮,设计制造了长短齿整体粗切滚刀,提高了刀具的耐用度和齿轮精度。同时,基于滚削运动学,导出了适合于定量计算的滚削加工过程切削层参数的数学模型,并设计了性能较为完善的滚齿切削力测试系统,给出了综合描述滚削运动的方法。运用这种方法,对滚削中齿槽各断面廓形的创成过程,待切除余量的基本形体,刀齿切削刃上各工作点的切削厚度变化规律,以及切削力(力矩)变化规律等滚削运动特性参数进行了定量分析。     

Kinetic modelling of the dispersion of plutonium in the eastern Irish Sea: two approaches

A new model to simulate the dispersion of plutonium in the eastern Irish Sea is presented. The model solves the 3D hydrodynamic equations using normalized σ coordinates in the vertical simultaneously with the suspended matter equation. Pu can be present in three phases: water, suspended matter and bottom sediments. Reduction and oxidation reactions are also included in the model, in terms of reaction rates, since Pu can be present in the marine environment in principally two different oxidation states. Two kinetic models are presented to describe the transfers of radionuclides between the liquid and solid phases: a one-step model consisting of a single reversible reaction and a two-step model consisting of two consecutive reversible reactions. It has been found that both models can properly simulate the contamination of the waters and sediments from the eastern Irish Sea due to the releases from the BNFL Sellafield nuclear fuel processing plant, since the outputs from both models are very similar and in agreement with observations. Also, both models can simulate the speciation of Pu between the reduced and oxidized forms. However, if the dominant source of radionuclides to the water column is redissolution from a contaminated sediment, a process that is actually occurring in the Irish Sea, it has been found that a two-step model must be used. Indeed, a one-step model predicts the redissolution from the sediment to be unrealistically rapid.     

A simultaneous route-level transit patronage model: demand,supply, and inter-route relationship

In this paper we present a route-level patronage model that incorporates transit demand, supply and inter-route effects in a simultaneous system. The model is estimated at the route-segment level by time of day and direction. The results show strong simultaneity among transit demand, supply and competing routes. Transit ridership is affected by the level of service, which in turn is determined by current demand and ridership in the previous year. The model demonstrates that a service improvement has a twofold impact on ridership; it increases ridership on the route with service changes, but it also reduces the ridership on competing routes so that the net ridership change is small. The model is thus useful for both system-level analysis and route-level service planning.     

蛋白质折叠过程中自回避搜索的算法研究

蛋白质折叠是一个复杂的演化过程。目前广泛采用HP格子模型，可以使分子内部连续的结构空间离散化，减少分子内部的自由度，从而较有效地研究蛋白质的折叠机理。在格子模型中，自回避路径的确定是搜索折叠构象的关键。文章在基于二维HP格子模型基础上，提出了一种简捷快速的自回避路径搜索算法，并在计算机上进行实例检测及模拟，产生效果较好的蛋白质折叠构象。但对于长序列，自回避路径折叠搜索计算时间将呈指数增长。为了更真实地模拟蛋白质折叠过程，文章进一步探讨了建立并行HP格子模型思路，对较长序列的折叠，其折叠过程不会因为序列长度的增加而快速增大模拟的复杂度，且符合生命的演化规律。     

结构模型参数变点的非参数检验

对于结构模型参数变点的检测问题，利用秩统计量，给出了模型只有一个变点的检验统计量，并且给出了一个计算检验渐近临界值的公式。     

综合交通运输的一种优化模型

随着社会经济发展和科技进步,人类交通运输业已经进入综合交通运输系统的新时代。将优化方法应用到交通运输问题中,通过系统、科学的研究,制定最优的交通运输方案,已经成为现在和将来交通运输研究的主题之一。通过对一种联合交通运输问题建立优化模型,并用实际的数值结果加以验证,以期能为企业的领导者合理、科学地决策最佳方案提供更加有力的依据。     

城市道路网络设计的数学模型及其解法

讨论了城市路网优化设计的通用模型，以及在离散变量和连续变量两种特殊情况下的路网设计模型，并分析了模型的解法。     

电动汽车全参数化车身平台化与模块化建模及性能带宽研究

为解决概念设计阶段电动汽车开发周期长等问题,基于隐式参数化方法提出一种电动汽车全参数化车身的平台化与模块化建模策略。首先将车身结构分解为上车体结构与下车体结构,根据设计要求对上下车体各自进行区域划分,定义各区域关键平台化衍生尺寸并进行基线总布置,形成平台化建模策略;然后基于平台化建模对下车体进行功能性模块划分,对上车体进行匹配性模块划分,分别进行参数化建模,形成模块化建模策略;最终建立了某款电动汽车车身的全参数化模型。结果表明,建模策略可实现不同车型的快速衍生,并且根据性能带宽规律,探究了轮距、轴距、车高、前端长度以及后端长度变化对刚度和模态性能的影响,有助于实现基于性能驱动的电动汽车车身与电池包的短周期开发。     

布置有真空绝热板的船用冷藏集装箱侧壁模型隔热性能的研究

内嵌真空绝热板的冷藏集装箱侧壁的隔热性能受布置工艺的影响较大,利用ANSYS软件,建立冷藏集装箱侧壁的仿真模型,制作布置有9块真空绝热板的侧壁实体,并测得其平均导热系数。结果表明,采用真空绝热板的块数越少,真空绝热板的边界热桥越短,其隔热效果越好;另外,在加强筋附近,应避免真空绝热板的拼接布置。